What is the Html DisplayFor syntax for

Question

I understand that in Razor   Html does a bunch of neat things  like generate HTML for links  inputs  etc   But I don t get the DisplayFor function     Why would I write    Html DisplayFor model   gt  model Title    when I could just write    Model Title

User · Answer

After looking for an answer for myself for some time, i could find something. in general if we are using it for just one property it appears same even if we do a "View Source" of generated HTML Below is generated HTML for example, when i want to display only Name property for my class

    <td>
    myClassNameProperty
    </td>
   <td>
    myClassNameProperty, This is direct from Item
    </td>

This is the generated HTML from below code

<td>
@Html.DisplayFor(modelItem=>item.Genre.Name)            
</td>

<td>
@item.Genre.Name, This is direct from Item
</td>

At the same time now if i want to display all properties in one statement for my class "Genre" in this case, i can use @Html.DisplayFor() to save on my typing, for least

i can write @Html.DisplayFor(modelItem=>item.Genre) in place of writing a separate statement for each property of Genre as below

@item.Genre.Name
@item.Genre.Id
@item.Genre.Description

and so on depending on number of properties.

User · Answer

Html DisplayFor   will render the DisplayTemplate that matches the property s type   If it can t find any  I suppose it invokes  ToString       If you don t know about display templates  they re partial views that can be put in a DisplayTemplates folder inside the view folder associated to a controller     Example   If you create a view named String cshtml inside the DisplayTemplates folder of your views folder  e g Home  or Shared  with the following code    model string   if  string IsNullOrEmpty Model         lt strong gt Null string lt  strong gt    else       Model     Then  Html DisplayFor model   gt  model Title   assuming that Title is a string  will use the template and display  lt strong gt Null string lt  strong gt  if the string is null  or empty

User · Answer

DisplayFor is also useful for templating  You could write a template for your Model  and do something like this    Html DisplayFor m   gt  m    Similar to  Html EditorFor m   gt  m   It s useful for the DRY principal so that you don t have to write the same display logic over and over for the same Model   Take a look at this blog on MVC2 templates  It s still very applicable to MVC3   http   www dalsoft co uk blog index php 2010 04 26 mvc-2-templates     It s also useful if your Model has a Data annotation  For instance  if the property on the model is decorated with the EmailAddress data annotation  DisplayFor will render it as a mailto  link

User · Answer

I think the main benefit would be when you define your own Display Templates  or use Data annotations   So for example if your title was a date  you could define    DisplayFormat DataFormatString     0 d       and then on every page it would display the value in a consistent manner   Otherwise you may have to customise the display on multiple pages  So it does not help much for plain strings  but it does help for currencies  dates  emails  urls  etc    For example instead of an email address being a plain string it could show up as a link    lt a href  mailto  ViewData Model  gt  ViewData TemplateInfo FormattedModelValue lt  a gt

[asp.net-mvc-3] What is the @Html.DisplayFor syntax for?

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